This invention relates to a resin mold semiconductor device and also to a technique for sealing the same.
In fabricating a semiconductor integrated circuit (hereinafter called an "IC"), a number of IC units are generally fabricated integrally with one another, the integrated article is then molded inside a mold for each IC unit using a resin and after unnecessary portions such as leads are punched out, the resulting molded article is separated into the IC units.
In the resin molding method in the conventional IC fabrication procedures, a transfer molding method using a heat-setting resin such as an epoxy resin or a silicone resin has been widely employed. According to this molding method, a specific molding apparatus equipped at its mold with a runner for charging a molding resin and a dam for preventing outflow of the resin from the mold in necessary. Moreover, since not a short period of time (60 to 180 seconds) is necessary for the resin to be cured, productivity is low. Moreover, because the resin undergoes curing inside the runner, the resin is wasted.
In view of these drawbacks of the resin molding method, the Applicant of this invention previously proposed an invention entitled "Molding method of integrated circuit" as Japanese Patent Application No. 22909/1975 (Japanese Patent Laid-Open No. 98969/1976). The invention disclosed in the prior patent application is characterized by clamping one unit of an IC by upper and lower molded articles that are prepared in advance, and then coupling the molded articles together at the clamp portion. Though this method is suited for mass-production and remarkably reduces the quantity of a necessary resin, it is not free from the drawbacks that the IC main body tends to be broken due to mechanical or thermal impact applied thereto at the time of coupling of the molded articles and the semiconductor element undergoes degradation of its characteristics since the moisture stays in gaps inside the molded articles after their coupling and sealing.